A percentile (or a centile) is a measure used in statistics indicating the value below which a given percentage of observations in a group of observations falls.
For example, the 20th percentile is the value (or score) below which 20% of the observations may be found.
Equivalently, 80% of the observations are found above the 20th percentile.
Percentiles are used in statistics to give you a number that describes the value that a given percent of the values are lower than.
Example: Let’s say we have an array of the ages of all the people that lives in a street.
ages = [5,31,43,48,50,41,7,11,15,39,80,82,32,2,8,6,25,36,27,61,31]
What is the 75. percentile?
The answer is 43, meaning that 75% of the people are 43 or younger.
